4 
TfiE CRETACEOUS ROCKS OF BRITAIN. 
Cuvieri. His 3 II., or “ Chalk without flints and with few organic 
remains/’ is the upper part of our Lower Chalk, and his Grey Chalk 
includes what was then usually called Chalk Marl. 
From this it will be seen that Phillips made a very near approach 
to the modern mode of subdivision. He particularly notes the bed 
of soft marl (zone of Actinocamax plenus ) which forms such a 
marked horizon between the two parts of his “ Chalk without flints,” 
and if he had only taken this clear physical line of demarcation, 
instead of making the presence or absence of flints his criterion, his 
divisions could have been accepted at the present time. 
Phillips’s description of the Dover Chalk was reproduced in Cony- 
beare and Phillips’s “ Outlines of the Geology of England and Wales ” 
(1822). In this book, however, the Chalk is separated from the 
Chalk Marl, and with the latter are included the Upper Greensand 
and Gault, the authors being under the erroneous impression that 
the Folkestone clay was an argillaceous portion of the Chalk Marl 
and that the Firestone beds or Upper Greensand were subsidiary beds 
in this formation (see Vol. I. of this Memoir, p. 21). Phillips’s 
Grey Chalk is therein regarded as the upper or more calcareous 
portion of a Chalk Marl Group. (See “ Outlines,” pp. 104,126.) 
Mantell’s “Fossils of the South Downs” was published in 1822, 
and he also classes the Gault and Chalk Marl together, calling the 
former “ Blue Chalk Marl,” and the latter “ The Grey Chalk Marl.” 
The Chalk, as distinct from the Chalk Marl, he only separates into 
Lower without flints and Upper with flints, but indicates no line of 
demarcation, so that many of his Upper Chalk fossils belong really 
to the Middle Chalk. 
From 1822 to 1859 every English writer on the Chalk, with two 
exceptions, continued to use the vague and unsatisfactory divisions 
of : — 
Upper Chalk with flints, 
Lower Chalk without flints, :■ 
Chalk Marl and Grey Chalk, 
without attempting to define the limits between them. 
The two exceptions were Samuel Woodward, in 1833, and Daniel 
Sharpe, in 1853. 
Woodward’s division of the Norfolk Chalk* was not unlike that 
of W. Phillips, being into four parts, as below : — 
Upper Chalk w T ith many flints. 
Medial Chalk with few flints. 
Lower Chalk without flints. 
Chalk Mail. 
He roughly indicated the areas occupied by these divisions on 
his sketch map of Norfolk, but gave no exact indication of the limits 
between them. It is probable that his “ lower or hard chalk ” in¬ 
cluded beds which are now regarded as the base of the Middle Chalk, 
and that his Medial Chalk comprised beds both above and below 
* An Outline of the Geology of Norfolk, 4to and 8vo, Norwich, 1833, 
with a geological sketch map and plates of fossils. 
